The measurement of cortisol in saliva has become a reliable tool for both thc scientist and the clinician for studying adrenal cortical function in the adult. We have measured salivary cortisol in samples from 138 healthy infants, children, and adolescents, and from 14 adults. Saliva samples were obtained at home using a cotton swab and a saliva-collecting tube at 800, 1300, and 1800 h before meals. Cortisol was measured using a time-resolved fluorcsccnt irnmunoassay. Cortisol levels in saliva ranged from less than 2 nmol/L up to more than 100 nmol/L. Cortisol levels were age-dependent. Intcrcstingly, after thc age of 6 y, cortisol levcls corrclated significantly with pubertal stages (analysis of variance). No sex difference was found. In addition, cortisol morning levels and daily cortisol levels (area under the curve from three measurements) increased with body weight and body mass index. The highest cortisol levels were measured in saliva of children younger than 1 y. No circadian variation was evident before thc agc of 9 mo. After 1 y of age, salivary cortisol levels varied in a circadian fashion. The measurement of salivary cortisol levels is an attractive way of testing adrenal function in infants and children. It provides a rcliable tool for the determination of the physiology and developmental characteristics of cortisol metabolism. (Pediatr Res 37: 502-506, 1995)The measurement of cortisol in saliva provides a reliable cents and from 1 4 adults to obtain more insight into regulatory tool for investigations of hypothalamus-pituitary-adrenal axis mechanisms of adrenal function throughout childhood and activity (1-1 1). Saliva samples can be obtained stress-free. In adolescents. addition, salivary cortisol reprcsents the free fraction of cortisol in plasma and does not depend on salivary sccretion rate (flow rate) nor on salivary protein content (4, 5, 9, 11). About METHODS 5-10% of total plasma cortisol is not bound to cortisol-binding Subjects and study protocol. Saliva samples were obtained globulin (= free plasma and diffuses into in the home setting at 800, 1300, and 1800 h before meals. saliva. Salivary cortisol measurements have been extensively Saliva samples were sent to the laboratory by surface mail. A used in psychobiologic, psychiatric, and endocrine re-complete medical examination was performed, and height, search. Surprisingly, relatively little information is available on weight, and pubertal stages were recorded by means of a the use of salivary cortisol determinations in children and standardized examination form. adolescents. Importantly, relatively few studies deal with the Height, weight, and body mass index values of the subjects diurnal variation of cortisol levels in children, developmental were all within the third to 97th percentile range (26). A total and physiologic aspects of function in young age, and of 178 healthy subjects were recruited from an inner city influ' ' ' ' of and pubertal On neighborhood (Munich, Germany), the local kindergarden, and cortisol levels (12)(13)(14)...

Secretory patterns of LH and testosterone were characterized in the intact male miniature pig. All blood samples were taken from indwelling catheters. Hourly sampling was carried out over 24 h and during a morning period blood was collected for 2 h at 10 min intervals. No significant difference was detected in the plasma LH concentration on the basis of hourly sampling. Plasma testosterone was significantly (P less than 0-05) lower during the evening and night when compared with morning values. The second experiment was concerned with the pattern of plasma LH and testosterone concentrations before and after copulation. Blood sampling was performed at 10 min intervals. Plasma LH was significantly (P less than 0-001) raised for 30 min after copulation when compared with any 30 min period (0-120 min) before copulation. Plasma testosterone was not significantly altered for any 30 min period of the experiment (0-270 min). The data are interpreted as a possible mechanism for endocrine control of testicular function.

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Administration of tetracosactid into male rabbits, fitted with permanently indwelling jugular catheters, resulted in a rapid rise of plasma corticosteroids and plasma testosterone. Corticosteroid concentrations were significantly elevated at 40 and 60 min and testosterone concentrations 20 min after the iv injection of tetracosactid (2.5, 5.0, and 10.0 \g=m\g/kg body weight), in comparison to pre-treatment levels. Corticosteroid values in plasma were elevated as long as 120 min after tetracosactid injection.In contrast, testosterone levels were lower at 60\p=n-\120min after tetracosactid injection than corresponding pre-treatment values. However, these differences were not significant. At the doses used no tetracosactiddose-dependent corticosteroid or testosterone release could be found; apparently, testosterone release is only dependent upon basal plasma levels but not upon the dose of tetracosactid applied. From these studies it is concluded that tetracosactid may bring about an increase or decrease of testosterone concentration in plasma in the buck depending upon the length of time elapsing between injection of tetracosactid and blood withdrawal.It has been shown that administration of short term ACTH over a period of several days significantly suppresses plasma testosterone in normal adult human males (Sorcini et al. 1963; Rivarola et al. 1966; Beitins et al. 1973;Irvine et al. 1974; Doerr 8c Pirke 1975. This ACTH-induced suppression of testo¬ sterone is apparently not due to an inhibition of luteinizing hormone (Beitins et al. 1973;Irvine et al. 1974;Doerr &· Pirke 1975. According to Doerr 8c Pirke (1976) the similarities between the ACTH-and cortisol-induced sup-

We investigated the effects of dopamine, met-enkephalin and leu-enkephalin on basal and ouabain-stimulated release of oxytocin and vasopressin from isolated neurointermediate lobes. The present study revealed that neurohypophyseal hormone release was not affected by dopamine, neither from lobes of untreated rats nor from those of rats with dopamine-deficiency (pretreated with alpha-methyl-p-tyrosine-methylester). Likewise, metoclopramide, a dopamine antagonist, was unable to alter the neurohypophyseal hormone release. Our results also indicate that the opioid peptides met-enkephalin and leu-enkephalin do not influence spontaneous or ouabain-stimulated oxytocin and vasopressin release, which is in accordance with our findings that naloxone under our experimental conditions is also ineffective.