B J Looij

Leids Universitair Medisch Centrum, Leiden, South Holland, Netherlands

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Publications (9)24.03 Total impact

  • Article: The effect of GHRH on TSH release in rats in vivo and in vitro.
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    ABSTRACT: In man, GHRH has been shown to potentiate the TSH-releasing activity of TRH. To study the way by which GHRH affects TRH-stimulated TSH release, we examined the effect of GHRH (1-29)NH2 on basal and stimulated TSH secretion in intact male rats and superfused dispersed rat pituitary cells. In the intact rats, GHRH(1-29)NH2 potentiated TRH-stimulated TSH release in the evening, but potentiation was not observed in the morning and in dispersed pituitary cells. Basal TSH levels were not changed by GHRH(1-29)NH2. It is concluded that GHRH(1-29)NH2 potentiates the TSH-releasing activity of TRH in the evening in rats possibly through suprahypophyseal disinhibition.
    Journal of endocrinological investigation 04/1995; 18(3):214-9. · 1.57 Impact Factor
  • Article: The interaction of GHRH with TRH in acromegaly: a controlled study.
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    ABSTRACT: In a single-blind placebo-controlled study, the effect of an iv bolus injection of 100 micrograms GHRH(1-29)NH2 on the response to 200 micrograms TRH was assessed in 10 untreated patients with acromegaly to determine whether GHRH interacts with TRH in acromegaly, as previously described in healthy subjects. The combination of GHRH(1-29)NH2 with TRH resulted in a larger increment of peak and of integrated plasma TSH and PRL levels than after TRH alone. GHRH alone had no effect on TSH secretion and only a modest effect on PRL secretion. These findings suggest that in acromegaly, like in healthy individuals, GHRH potentiates the TSH response to TRH and that the effects of GHRH and TRH on PRL secretion are additive.
    Acta endocrinologica 11/1991; 125(4):337-41.
  • Article: Plasma interleukin-1, tumour necrosis factor and hypothalamic-pituitary-adrenal axis responses during migraine attacks.
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    ABSTRACT: To evaluate systemic cytokine and hypothalamic-pituitary-adrenal axis responses in migraine, we measured plasma levels of tumour necrosis factor, interleukin-1, adrenocorticotropic hormone, and cortisol, as well as body temperature during and between attacks in 20 migraine patients. We found no evidence of systemic rise of cytokines during migraine attacks. Plasma cortisol and adrenocorticotropic hormone responses were similar to those found to experimentally-induced pain in normal subjects, i.e. elevated cortisol and unchanged adrenocorticotropic hormone levels. Unexpectedly, body temperature tended to be lower during attacks.
    Cephalalgia 06/1991; 11(2):65-7. · 3.43 Impact Factor
  • Article: The effect of calcitonin on growth hormone secretion in acromegaly.
    B J Looij, F Roelfsema, M Frölich
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    ABSTRACT: To determine whether human calcitonin inhibits GH secretion in acromegaly, as previously described for healthy subjects, the effect of an i.v. bolus injection of calcitonin or saline on GH levels in patients with active acromegaly was studied and compared to that of an i.v. bolus injection of the synthetic somatostatin analogue, octreotide. After the injection of calcitonin, GH levels decreased by 46% of initial values, whereas octreotide reduced GH levels by 87% and saline had no significant effect. Administration of calcitonin to acromegalics did not cause the transient rise in plasma PRL and TSH levels seen in normal subjects. Octreotide induced a decrease in plasma PRL in three out of seven patients. It is concluded that human calcitonin suppresses GH secretion in acromegaly, but not to normal levels; moreover the effect is less than that found for octreotide. In addition, acromegalic patients did not exhibit the PRL and TSH-releasing activity of calcitonin found in normal subjects, while octreotide inhibited PRL secretion in some acromegalic patients.
    Clinical Endocrinology 12/1989; 31(5):573-9. · 3.17 Impact Factor
  • Article: [Hereditary onycho-osteodysplasia (HOOD)].
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    ABSTRACT: Hereditary onycho-osteodysplasia (HOOD) is an autosomal dominant condition, characterized by dysplasia of the nails and joints and extra bone formation at the os ilium. Nephropathy occurs in some families with HOOD. We discuss a patient's history and the results of the study of her family. The incidence of all important features of this syndrome is given. Finally, some methods of treatment and genetic counseling are discussed.
    Tijdschrift voor kindergeneeskunde 01/1989; 56(6):298-303.
  • Article: The effect of calcitonin on growth hormone secretion in man.
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    ABSTRACT: To determine whether human calcitonin inhibits GH secretion in man, as has been described for salmon calcitonin, the effect of an i.v. bolus of human calcitonin or saline on GH release after either insulin-induced hypoglycaemia or the administration of GH-releasing hormone (GHRH) or saline was studied. After the injection of calcitonin, no spontaneous GH surges were seen; the GH response to hypoglycaemia was diminished and the response to GHRH almost completely suppressed. Administration of calcitonin also caused a small and transient rise in plasma PRL and TSH but not LH levels, and no change in the integrated PRL or TSH response. Calcium and magnesium levels did not change. It is concluded that human calcitonin suppresses GH secretion in man, but not by suppressing GHRH and probably not by increasing somatostatin release. In addition, calcitonin has limited PRL and TSH-releasing activity.
    Clinical Endocrinology 12/1988; 29(5):517-27. · 3.17 Impact Factor
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    Article: Genetic counselling in hereditary osteo-onychodysplasia (HOOD, nail-patella syndrome) with nephropathy.
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    ABSTRACT: Hereditary osteo-onychodysplasia (HOOD, nail-patella syndrome) is an autosomal dominant condition characterised by nail dysplasia, patellar hypoplasia or aplasia, and nephropathy. The risk for HOOD patients to have a child with HOOD who will develop renal failure cannot easily be deduced from published pedigrees. We have studied a large family with 30 patients with HOOD and have analysed 34 kindreds with HOOD nephropathy from published reports, comprising 213 patients. For a patient with HOOD from a family in which HOOD nephropathy occurs, the risk of having a child with HOOD nephropathy is about 1:4; the risk of having a child in whom renal failure will develop is about 1:10.
    Journal of Medical Genetics 11/1988; 25(10):682-6. · 6.36 Impact Factor
  • Article: The interaction of growth hormone releasing hormone with other hypothalamic hormones on the release of anterior pituitary hormones.
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    ABSTRACT: To determine whether the 29 amino-acid fragment of growth hormone releasing hormone (GHRH) can be combined with other hypothalamic releasing hormones in a single test of anterior pituitary reserve, the responses of anterior pituitary hormones to combinations of an i.v. bolus of GHRH(1-29)NH2 or saline with an i.v. bolus of either LH releasing hormone (LHRH) plus TRH, ovine CRH(oCRH) or saline were studied. Each infusion of GHRH(1-29)NH2 resulted in a rapid increment of the plasma GH value. Infusion of GHRH(1-29)NH2 also caused a small and transient rise in plasma PRL, but no change in the integrated PRL response. The combination of GHRH(1-29)NH2 with LHRH plus TRH caused a larger increment of peak and integrated plasma TSH levels than LHRH plus TRH alone. GHRH(1-29)NH2 did not affect the release of other anterior pituitary hormones after infusion with oCRH or LHRH plus TRH. Because of the finding of potentiation of the TSH-releasing activity of LHRH plus TRH by GHRH(1-29)NH2, the study was extended to the investigation of TSH release after infusion of TRH in combination with either GHRH(1-29)NH2 or GHRH(1-40). In this study the combination of TRH with both GHRH preparations also caused a larger increment of the peak and integrated plasma TSH levels than TRH alone. It is concluded that GHRH(1-29)NH2 possesses moderate PRL-releasing activity apart from GH-releasing activity. In addition, GHRH potentiates the TSH-releasing activity of TRH.(ABSTRACT TRUNCATED AT 250 WORDS)
    Clinical Endocrinology 03/1986; 24(2):149-56. · 3.17 Impact Factor
  • Article: Glucagon-stimulated plasma C-peptide and insulin levels in active and non-active acromegalics.
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    ABSTRACT: The glucagon-stimulated insulin and C-peptide release in patients with active acromegaly, cured acromegalic patients and healthy controls were studied. There was an elevation of the fasting insulin levels in active acromegalics and the fasting C-peptide levels in both patient groups. After i.v. injection of glucagon the insulin and C-peptide levels increased. The highest levels were recorded in active acromegalics, but cured patients also had higher levels than the control group. The insulin/C-peptide ratio was increased in active acromegalics in comparison with that found for inactive acromegalics and normal controls. In addition, the plasma half-lives (T1/2) of endogenous insulin and C-peptide were measured. It was found that the T1/2 for insulin was increased in active acromegalics only. From this study we conclude that even when the treatment of acromegaly is effective insulin and C-peptide secretion do not normalize due, probably, to increased synthesis and release upon stimulation of the pancreatic beta-cells. In active acromegaly the removal of insulin is probably also reduced.
    Clinical Endocrinology 01/1986; 23(6):627-34. · 3.17 Impact Factor