Prasanth K Chelikani

• BVSc, MVSc, PhD
• Professor at Texas Tech University

Like humans, cats have a strong relationship between decreasing insulin sensitivity and the development of diabetes with obesity. However, the underlying molecular mechanisms of impaired insulin secretion and signaling in cats remain largely unknown. A total of 54 client-owned nondiabetic lean (n = 15), overweight (n = 15), and diabetic (n = 24) ca...

Background Body condition score (BCS) is a subjective tool and the deposition of subcutaneous fat differs from the deposition of abdominal fat. Objective The aim of this study was to evaluate by multivariate regression models and ultrasonography the amount of fat accumulated in different areas of the abdominal cavity in Jersey non‐pregnant non‐lac...

Smoothelin-like 1 (SMTNL1) is expressed in smooth and skeletal muscle tissues as well as a variety of steroid hormone-sensitive tissues. SMTNL1 can play a sex-dependent regulatory role in skeletal muscle metabolism in mice. Previous studies have documented appreciable changes in muscle morphology and metabolic function of young male mice with genet...

Fatty acid amide hydrolase (FAAH) degrades the endocannabinoid anandamide. A polymorphism in FAAH (FAAH C385A) reduces FAAH expression, increases anandamide levels, and increases the risk of obesity. Nevertheless, some studies have found no association between FAAH C385A and obesity. We investigated whether the environmental context governs the imp...

Hypocalcemia remains a common metabolic disorder of dairy cattle; therefore, an efficient prevention is still challenging. Among the various prevention strategies for hypocalcemia is the use of anionic compounds to induce a mild metabolic acidosis during the prepartum period. Acid-base status can be readily assessed through urine pH. Accordingly, a...

Fatty acid amide hydrolase (FAAH) degrades the endocannabinoid anandamide. A polymorphism in FAAH (FAAH C385A) reduces FAAH expression, increases anandamide levels, and increases the risk of obesity. Nevertheless, some studies have found no association between FAAH C385A and obesity. We investigated whether the environmental context governs the imp...

Mol. Nutr. Food Res. 2022, 66, 202100653 DOI: 10.1002/mnfr.202100653 High protein diets containing egg or whey protein, together with inulin fiber and exercise, improved energy balance in obese rats by decreasing food intake partly through the gut hormone cholecystokinin, enhancing energy expenditure, and decreasing fat mass. Interestingly, the die...

Scope: Dietary protein, prebiotic fiber and exercise individually have been shown to aid in weight loss; however less is known of their combined effects on energy balance. We determined the effects of diets high in protein and fiber, with exercise, on energy balance, hormones and gut microbiota. Methods and results: Obese male rats were fed high...

The objectives of this cross-sectional, nonintervention, observational study were to compare urine and blood parameters between cows consuming a positive dietary cation-anion difference (DCAD) diet [early dry cows, DCAD + 250 mEq/kg of dry matter (DM), n = 15] with the same cows consuming a negative DCAD diet (−220 mEq/kg of DM) 10 d after moving t...

Diets supplemented with protein and fiber are well known to reduce food intake and weight gain; however, less is known about the combined effects of protein and fiber on energy balance and gut microbiota composition. We compared effects of diets containing egg or whey protein with cellulose or inulin fiber on energy balance, gut microbiota, hormone...

Low protein diets are associated with increased lifespan and improved cardiometabolic health primarily in rodents, and likely improve human health. There is strong evidence that moderate to severe reduction in dietary protein content markedly influences caloric intake and energy expenditure, which is often followed by a decrease in body weight and...

Pituitary pars intermedia dysfunction (PPID) is a common endocrine disorder of aged horses, with muscle atrophy as one of the clinical signs. We sought to compare muscle mass and regulation of skeletal muscle proteolysis between horses with PPID and muscle atrophy to older horses without PPID, and to assess the impact of treatment with pergolide (d...

Background: Whey protein (WH)-enriched diets are reported to aid in weight loss and to improve cardiovascular health. However, the bioactive components in whey responsible for causing such effects remain unidentified. Objective: We determined the effects of whey and its components [α-lactalbumin (LA) and lactoferrin (LF)] on energy balance, gluc...

Background: Both diabetes mellitus (DM) and obesity are common in cats. The adipokines leptin, adiponectin, resistin and omentin are thought to have important roles in human obesity and glucose homeostasis; however, their functions in the pathophysiology of feline diabetes mellitus and obesity are poorly understood. We determined whether sexual di...

The objective was to determine effects of feed restriction and refeeding on reproductive development and energy balance in pre-pubertal male rats. Sprague Dawley rats (n = 32, 24 days old, ~65 g), were randomly allocated into four treatments (n = 8/treatment): (1) Control (CON, ad libitum feed; (2) Mild Restriction (MR, rats fed 75% of CON consumpt...

Scope: Dietary protein restriction elicits hyperphagia and increases energy expenditure; however, less is known of whether these responses are a consequence of increasing carbohydrate content. We determined the effects of protein diluted diets with fixed carbohydrate content on energy balance, hormones, and key markers of protein sensing and therm...

Objectives Fermentation of fiber in the gut generates short-chain fatty acids (SCFA), such as butyrate, which decrease food intake and promote weight loss in rodent models. SCFA have been shown to enhance secretion of the gut satiety hormone peptide YY (PYY). However, it is unknown whether PYY is causative to SCFA-induced changes in energy balance....

Objectives Metabolic syndrome encompasses obesity, glucose intolerance, hypertension and dyslipidemia, and is a global health concern; however, the interactions between diet and host physiology that predispose to metabolic syndrome are incompletely understood. Our Objectives were to determine the effects of high-fat diet (HFD) on energy balance, gu...

Total amino acid (AA) restriction promotes hyperphagia and energy expenditure. We determined whether (i) methionine restriction mimics the effects of total AA restriction, (ii) methionine supplementation attenuates these responses, and iii) sympathetic signaling mediates such effects. Rats were injected with either vehicle (V) or 6-hydroxydopamine...

Metabolic syndrome encompasses obesity, glucose intolerance, hypertension, and dyslipidemia; however, the interactions between diet and host physiology that predispose to metabolic syndrome are incompletely understood. Here, we explored the effects of a high‐fat diet (HFD) on energy balance, gut microbiota, and risk factors of metabolic syndrome in...

Gastrointestinal hormone based therapies are being investigated for treating diabetes in cats; however, the tissue distribution of these hormones and their cognate receptors remain largely understudied. We determined the distribution of transcripts for the gut hormones proglucagon (Gcg), glucose-dependent insulinotropic peptide (Gip), peptide YY (P...

Moderate dietary protein restriction promotes hyperphagia and thermogenesis; however, little is known of whether these responses are due to restriction of the essential amino acids tryptophan and histidine. Here, we determined whether restriction of tryptophan and histidine alone recapitulate the effects of total amino acid restriction on energy ba...

Significance We present evidence that an endocannabinoid-dependent signaling mechanism contributes to the hypophagic actions of leptin. Specifically, leptin increases fatty acid amide hydrolase (FAAH) activity and reduces N -arachidonoylethanolamine (anandamide; AEA) signaling, particularly within the hypothalamus, to promote a suppression of food...

Inulin, a popular prebiotic fiber, has been reported to promote satiety and fat loss; however, the dose-response effects of inulin on energy balance and diet preference, and whether the metabolic effects are independent of calorie restriction are not well characterized. Therefore, we compared the effects of diets varying in inulin concentrations on...

Background: Mycophenolate mofetil (MMF) is commonly prescribed after transplantation and has major advantages over other immunosuppressive drugs, but frequent gastrointestinal (GI) side-effects limit its use. The mechanism(s) underlying MMF-related GI toxicity have yet to be elucidated. Methods: To investigate MMF-related GI toxicity, experiment...

Objective: To determine the effects of graded dietary restriction of tryptophan on food intake, energy expenditure, body composition, gut hormones, and select fecal bacterial populations in obesity-prone rats. Methods: Obesity-prone rats were randomized to isocaloric diets with varying degrees of tryptophan restriction: control (100% requirement...

Whey protein promotes weight loss and improves diabetic control, however, less is known of its bioactive components that produce such benefits. We compared the effects of normal protein (control) diet with high protein diets containing whey, or its fractions lactalbumin and lactoferrin, on energy balance and metabolism. Diet-induced obese rats were...

Dairy proteins-whey protein, in particular-are satiating and often recommended for weight control; however, little is known about the mechanisms by which whey protein and its components promote satiety and weight loss. We used diet-induced obese rats to determine whether the hypophagic effects of diets that are enriched with whey and its fractions,...

Objective To determine the effects of exogenous glucagon-like peptide-2 (GLP-2), with or without massive distal bowel resection, on adaptation of jejunal mucosa, enteric neurons, gut hormones and tissue reserves in rats. Background GLP-2 is a gut hormone known to be trophic for small bowel mucosa, and to mimic intestinal adaptation in short bowel...

Background Dyslipidemia, dysregulated adipokine secretion and alteration in glucagon and adropin concentrations are important obesity-related factors in the pathophysiology of human Type 2 diabetes; however, their roles in the pathophysiology of feline diabetes mellitus are relatively unknown. Here, we determined the concentrations of circulating l...

Objective: To determine whether diets enriched with the whey protein components lactalbumin and lactoferrin interact additively with inulin to improve energy balance by decreasing food intake and body weight (BW). Methods: In four experiments, diet-induced obese rats were randomized to diets containing either lactalbumin or lactoferrin at low (2...

Bariatric surgeries promote weight loss and improve diabetic control; however, the underlying mechanisms are poorly understood. Of the bariatric operations, sleeve gastrectomy (SG) is becoming increasingly popular because of its relative technical simplicity, with effects on both weight loss and diabetic control being nearly comparable to more comp...

High-fat diets induce obesity and increase risks of diabetes, cardiovascular and renal disorders. Whey or casein enriched diets decrease food intake and weight gain; however, their cardiovascular and renal benefits are unclear. We determined whether whey and casein enriched diets improve energy balance and are protective against renal damage and mo...

Diets deficient in protein often increase food consumption, body weight and fat mass; however, the underlying mechanisms remain poorly understood. We compared the effects of diets varying in protein concentrations on energy balance in obesity-prone rats. We demonstrate that protein-free (0% protein calories) diets decreased energy intake and increa...

Our objectives were to measure plasma concentrations of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) in client-owned newly diagnosed diabetic cats and nondiabetic lean or overweight cats and to determine whether circulating concentrations of these hormones differed between study groups and if...

BACKGROUND: Dietary whey and casein proteins decrease food intake and body weight and improve glycemic control; however, little is known about the underlying mechanisms. OBJECTIVE: We determined the effects of dietary whey, casein, and a combination of the 2 on energy balance, hormones, glucose metabolism, and taste preference in rats. METHODS: In...

Dietary fat supplementation during the periparturient period is one strategy to increase energy intake and attenuate the degree of negative energy balance during early lactation; however, little is known of the underlying hormonal and metabolic adaptations. We evaluated the effects of prepartum fat supplementation on energy-balance parameters and p...

Bariatric surgeries produce weight loss with improvements in diabetic control through multiple mechanisms, including enhanced stimulation of the lower gut. The ileal transposition surgery was initially developed to gain insights into the lower gut mechanisms that contribute to the anorexic and weight loss effects of roux-en-Y gastric bypass, withou...

Background: Enhanced stimulation of the lower gut is hypothesized to play a key role in the weight loss and resolution of diabetes following bariatric surgeries. Ileal transposition (IT) permits study of the effects of direct lower gut stimulation on body weight, glucose homeostasis and other metabolic adaptations without the confounds of gastric...

Bariatric surgeries are hypothesized to produce weight loss and improve diabetes control by multiple mechanisms including gastric restriction and lower gut stimulation; the relative importance of these mechanisms remains poorly understood. We compared the effects of a typical foregut procedure - Sleeve Gastrectomy, (SG) with a primarily hindgut sur...

Peptide YY (3-36) [PYY(3-36)] is postulated to act as a hormonal signal from gut to brain to inhibit food intake. PYY(3-36) potently reduces food intake when administered systemically or into the brain. If action of endogenous PYY(3-36) is necessary for normal satiation to occur, then pharmacological blockade of its receptors should increase food i...

Background Roux-en Y gastric bypass (RYGB) and ileal transposition (IT) surgeries produce weight loss and improve diabetic control; however, the mechanisms of glycemic improvements are largely unknown. Because skeletal muscle and liver play a key role in glucose homeostasis, we compared the effects of RYGB and IT surgeries on key molecules of gluco...

The role of distal gut signals in control of feed intake and metabolism in cattle has received scant attention. Peptide YY (PYY) and glucagon-like peptide-1, which are secreted from enteroendocrine cells of the distal gut in monogastrics have several functions, including regulation of energy balance. However, little is known of the tissue expressio...

Weight loss in obese humans produces a relative leptin deficiency, which is postulated to activate potent orexigenic and energy conservation mechanisms to restrict weight loss and promote weight regain. Here we determined whether leptin replacement alone or with GLP-1 receptor agonist exendin-4 attenuates weight regain or promotes greater weight lo...

The hypothalamus and brain stem have important roles in regulating food intake; the roles of other nonhomeostatic centers in detecting nutrient content of ingested food have been poorly characterized. We used blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) to map brain regions that are responsive to intragastric infus...

The gut hormone peptide YY(3-36)-amide [PYY(3-36)-NH(2)] is significantly more potent than PYY(1-36)-NH(2) in reducing food intake in rats and humans. Other Gly-extended and Ser(13)-phosphorylated PYY forms have been detected or predicted based upon known cellular processes of PYY synthesis and modification. Here we compared the effects of 3-h IV i...

Investigating the localization of gastric sensation within the brain is important for understanding the neural correlates of satiety. Previous rodent studies have identified the brain-stem and hypothalamus as key mediators of gastric distention-induced satiation. Although, recent blood oxygen level-dependent functional magnetic resonance imaging (B...

The signals that govern the upregulation of nutrient absorption (adaptation) after intestinal resection are not well understood. A Gastric Roux-en-Y bypass (GRYB) model was used to isolate the relative contributions of direct mucosal stimulation by nutrients, biliary-pancreatic secretions, and systemic enteric hormones on intestinal adaptation in s...

Roux-en-Y gastric bypass (RYGB) surgery is one of the most effective treatments for obesity producing long-term weight loss. The anorexia and weight loss from RYGB could be due to gastric restriction, malabsorption, enhanced lower gut stimulation, increased energy expenditure, and/or other metabolic adaptations. In ileal transposition (IT) surgery,...

The hormonal and metabolic signals that communicate the level of body energy reserves to the reproductive-mammary axis remain undefined in dairy cattle; consequently, our hypothesis was that leptin may fulfill this role. Our objectives were to determine the effects of diets differing in energy and protein density on dry matter intake (DMI), growth...

Chronic administration of anorexigenic substances to experimental animals by injections or continuous infusion typically produces either no effect or a transient reduction in food intake and body weight. Our aim here was to identify an intermittent dosing strategy for intraperitoneal infusion of peptide YY(3-36) [PYY(3-36)] that produces a sustaine...

Peptide YY (3-36) [PYY(3-36)] inhibits feeding in rodents, nonhuman primates and humans, yet the neural circuits underlying this action remain to be determined. Here we assessed whether PYY(3-36) inhibits feeding by activating neurons in forebrain and hindbrain sites containing Y2 receptors and linked to control of food intake, or in hindbrain site...

Chronic administration of anorexigenic substances to experimental animals by injections or continuous infusion typically produces no effect or a transient reduction in daily food intake and body weight. Our aim was to identify an intermittent dosing strategy for intraperitoneal infusion of salmon calcitonin (sCT), a homolog of amylin that produces...

Multi-drug therapy targeting different components of the energy regulatory system will likely be required to produce significant weight loss in obese individuals. An early step in developing such a therapy is defining the dose-response effects of anorexigenic compounds on food intake in animal models. We previously reported the dose-dependent effec...

Peptide YY(3-36) [PYY(3-36)] is a gut-brain peptide that decreases food intake when administered by intravenous infusion to lean and obese humans and rats. However, chronic administration of PYY(3-36) by osmotic minipump to lean and obese rodents produces only a transient reduction in daily food intake and weight gain. It has recently been shown th...

We used a conditioned taste aversion test to assess whether PYY(3-36) reduces food intake by producing malaise. Two-hour IV infusion of PYY(3-36) (8, 15, and 30 pmol/kg/min) at dark onset in non-food-deprived rats produced a dose-dependent inhibition of feeding and a conditioned aversion to the flavored chow paired with PYY(3-36) infusion. In food-...

Ghrelin stimulates, while glucagon-like peptide-1 (GLP-1) and peptide YY(3-36) [PYY(3-36)] inhibit, food intake and gastric emptying in rats. We determined the dose-dependent effects of a 3-h intravenous infusion of ghrelin at dark onset on food intake in freely feeding rats, and on the inhibitory effects of intravenous infusion of GLP-1 and PYY(3-...

The publisher regrets that this article is an accidental duplication of an article that has already been published, doi:10.1016/j.appet.2006.03.001. The duplicate article has therefore been withdrawn.

The gut hormone peptide YY(3-36) [PYY(3-36)] decreases food intake when administered by intravenous infusion to lean and obese humans and rats. Whether chronic administration of PYY(3-36) produces a sustained reduction in food intake and adiposity is the subject of intense debate. Batterham et al. (R. L. Batterham, M. A. Cowley, C. J. Small, H. Her...

Glucagon-like peptide-1(7-36)-amide (GLP-1) is postulated to act as a hormonal signal from gut to brain to inhibit food intake and gastric emptying. A mixed-nutrient meal produces a 2 to 3-h increase in plasma GLP-1. We determined the effects of intravenous infusions of GLP-1 on food intake, sham feeding, and gastric emptying in rats to assess whet...

Glucagon- like peptide- 1( 7 - 36)- amide ( GLP- 1) is postulated to act as a hormonal signal from gut to brain to inhibit food intake and gastric emptying. A mixed- nutrient meal produces a 2 to 3- h increase in plasma GLP- 1. We determined the effects of intravenous infusions of GLP- 1 on food intake, sham feeding, and gastric emptying in rats to...

Peptide YY (3-36) [PYY (3-36)] is postulated to act as a hormonal signal from the gut to the brain to inhibit food intake and gastric emptying. A mixed-nutrient meal produces a prolonged 2-3 h increase in plasma levels of both PYY (3-36) and PYY (1-36). We determined the dose-dependent effects of 3-h iv infusions of PYY (3-36) and PYY (1-36) (0.5-5...

We compared the effects of the two molecular forms of the brain-gut peptide YY (PYY), PYY(1-36) and PYY(3-36), on gastric emptying. Unanesthetized rats received 20-min intravenous infusions of rat PYY(1-36) (0, 1.7, 5, 17, 50, 100, 170 pmol x kg(-1) x min(-1)) and rat PYY(3-36) (0, 0.5, 1.7, 5, 17, 50, 100, 170 pmol x kg(-1) x min(-1)), either alon...

We determined the effects of feeding canola oil or infusing it into the abomasum on rumen fermentation, nutrient digestibility, duodenal flows of fatty acids, and milk composition in Holstein cows. Five ruminally and duodenally cannulated Holstein cows in late lactation were used in a 3 x 5 incomplete Latin square design. Treatments were 1) Control...

We determined the relative importance of cholecystokinin (CCK), leptin, and fatty acid concentrations in plasma in mediating the satiety effects of supplemental fat in lactating cows. Five ruminally and duodenally cannulated Holstein cows in late lactation were used in a 3 x 5 incomplete Latin square design with three treatments: 1) Control: basal...

We determined the effects of short-term fasting and refeeding on temporal changes in plasma concentrations of leptin, insulin, insulin-like growth factor- 1 (IGF-1), growth hormone (GH), glucose, and nonesterified fatty acids (NEFA), in early lactating cows, non-lactating pregnant cows, and postpubertal heifers. In experiment 1, Holstein cows in ea...

In this study we investigated the hormonal and metabolite responses to isoenergetic jugular infusions of glucose or lipid in early- and late-lactation Holstein cows. Six Holstein cows were used in a replicated Latin square design with jugular infusions of either 1) control (CON; saline), 2) glucose (GLU; 50% dextrose) or 3) lipid (LIP; 20% Intralip...

The objectives were to examine the effects of dietary energy and protein density on age and body composition at puberty, and on ovarian follicular dynamics during the pre- and peripubertal periods in Holstein heifers. In Phase 1, heifers were randomly allotted (n=10 per diet) at 100 kg body weight (BW) to diets with either low (P1L), medium (P1M) o...

Detection of leptin and leptin receptor mRNA in various tissues is crucial to an understanding of leptin physiology in dairy cattle. We report here evidence of leptin receptor gene expression in central and peripheral tissues of the bovine by reverse transcription and polymerase chain reaction analysis. Leptin mRNA was detectable in mammary parench...

An experiment was conducted with five Holstein cattle fitted with duodenal cannulae to identify and characterize gastrointestinal genes that are differentially expressed during conditions of hunger or satiety. Intestinal tissue samples were obtained from the duodenum, approximately 50-cm distal of the abomasal sphincter, using an endoscopy techniqu...