The demonstration in the central nervous system of a group of endogenous opioid-like substances has suggested their physiological role as neurotransmitter or neuromodulator in the control of hypothalamic-pituitary function. Recent studies have described a stimulatory effect of opioid substances on PRL, GH and TSH and an inhibitory influence on LH and FSH secretion. Naloxone, a specific opiate antagonist has been reported to prevent these effects (Morley 1981). Multiple endocrine disorders are present in diabetics, mainly characterized by altered basal secretion of pituitary hormones and impaired response to provocative stimuli. Recently it was observed that administration of TRH to diabetic subjects elicits abnormal secretion of FSH and GH

Weightman and Hall 1980) in both men and women, whereas growth hormone (GH) release by the pituitary remains unmodified, at least in normal men (Sowers, McCallum, Hershman, Carlson, Sturdevant and Meyer 1976). On the other hand, the administration of MCP to hypogonadal men significantly increases GH serum levels (Cohen, Hay, Beastall and Thomson 1979). Thus blood estrogen concentrations and/or the androgen/estrogen ratio may be important for the development of this response and may play a role in the control of the GH secretory system. To test this hypothesis the effect of an acute administration of MCP on serum GH concentrations in normal women was evaluated.

These data show that in diabetic, but not in normal subjects LVP enhances the GH responsiveness to secretagogues, such as GH-RH, clonidine and arginine, which act through three different mechanisms. These findings suggest that in diabetes mellitus, vasopressin functions as a primer for various GH responses.

In order to determine whether nicotine exerts its stimulant effect on serum concentrations of growth hormone (GH) by interacting with an adrenergic pathway, we evaluated the effect of cigarette smoking on the response of GH to the administration of clonidine, a specific a-adrenoceptor agonist. In six normal volunteers, clonidine significantly increased serum levels of GH. When subjects smoked two non-filter cigarettes, GH response to the a-adrenoceptor agonist was greatly enhanced. These findings suggest that in man nicotinic cholinergic and adrenergic mechanisms might interact in the stimulation of GH secretion.

Enzyme immunoassay (EIA) and electron microscopy (EM) were utilized to investigate the presence of rotavirus in feces of 388 children with acute enteritis hospitalized at the Hospital Santa Casa de Misericórdia in Porto Alegre, Brazil. The survey covered 12 months, beginning in July 1981. There were 162 rotavirus-positive cases (41.8%). During the period of the study rotavirus was detected throughout the year, but there was a striking seasonal variation (78.1% of cases) during January 1982.