Martı́n Palomar-Morales

Publications (2)0 Total impact

• Article: Prevention by l-arginine and polyamines of delayed development and embryotoxicity caused by chemically-induced diabetes in rats

  José D. Méndez, Martı́n Palomar-Morales
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  ABSTRACT: Diabetes mellitus induction with alloxan at a dose of 110 mg/kg i.p. in rats on Day 4 of pregnancy causes delayed development and resorptions as signs of embryotoxicity. In the present study, the administration of human NPH insulin at doses of 1 to 5 U/d to rats or 1.0 mL of 10 mM l-arginine for 8 d, starting the day following diabetes induction, prevented embryotoxicity and delayed development. Similar results were obtained when the polyamines putrescine, spermidine, or spermine were administered at doses of 1.0 mL of a 10 μM solution to each rat daily. However, even though L-arginine and polyamines prevented adverse effects of severe diabetes on the conceptus, and caused normalization of glucose, β-hydroxybutyrate levels remained elevated. These results support the hypothesis that the mechanisms of normal and altered development could be mediated by the action of polyamines.
  Reproductive Toxicology.
• Article: Effect of l-arginine on arginase activity in male accessory sex glands of alloxan-treated rats

  José D Méndez, Adriana Sosa, Martı́n Palomar-Morales
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  ABSTRACT: Arginase activity has been identified in the prostate, and may be important in the synthesis of polyamines in accessory sex glands in the male. Polyamines in turn may mediate the action of androgens. Diabetic patients have disordered androgen synthesis. The purpose of this work was to evaluate the effect of l-arginine on arginase activity in accessory sex glands of male rats under normal and diabetic conditions (alloxan 120 mg/kg, i.p.). Normal and diabetic male rats were untreated or were treated with insulin or l-arginine for 96 h, and sacrificed. Arginase activity was measured in serum and in accessory sex glands. Arginase activity in accessory glands did not change significantly with induction of diabetes. Arginase activity was increased in diabetic insulin-treated rats, but there was no arginase response to l-arginine administration in diabetic animals. These findings stand in contrast to beneficial effects of l-arginine previously observed when this amino acid was administered for a long time (at least 10 days). We suspect that altered arginase activity in accessory sex glands may play a role in the reproductive dysfunction caused by diabetes, inasmuch as arginase activity can be increased in experimentally diabetic rats by the administration of insulin.
  Reproductive Toxicology.