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W B Quay

Publications and source records attributed to W B Quay.

120 records · Page 7Linked to original sources
PubMedDate not supplied

Low molecular weight pineal and cerebral fractions affecting insulin secretion in vitro.

Studies were performed to examine the effects of various fractions of pineal gland origin upon rates of immunoreactive insulin release during short-term incubations of pancreatic islets from pinealectomized rats. Fractions of cerebral cortex were employed in control incubations. An ultrafiltrate of pineal extracts containing materials of molecular weight less than or equal to 1000 daltons stimulated insulin release while fractions of greater molecular weight were without effect. The stimulation of insulin release observed with the lower molecular weight pineal fraction was seen with both nonstimulatory (2 mM) and stimulatory (10 and 30 mM) medium glucose concentrations, but was abolished in the presence of 2,4-dinitrophenol (200 microM). Upon further fractionation of the low molecular weight pineal extract, fractions I (estimated molecular weight range 700-1000 daltons) and 11 (estimated molecular weight range 180-700 daltons) exhibited comparable stimulatory effects upon islet insulin release: similar effects were observed with cerebral cortical fractions in these molecular weight ranges. However, pineal fraction III (estimated molecular weight range less than 180 daltons) exhibited a striking inhibitory effect upon rates of insulin release compared to cerebral cortical fraction III. Potassium, dopamine, norepinephrine and epinephrine concentrations in both pineal and cortical tissue fractions were similarly low. We conclude that insulinotropic constituent(s) of similar molecular weight occur in pineal gland and cerebral cortex, and that the pineal insulinotropic activity stimulates active insulin secretion by the islets independently of concomitant stimulation by glucose; however, lower molecular weight insulinostatic constituent(s) are notable only in the pineal. It is suggested that mild hyperinsulinemia seen in pinealectomized rats under some circumstances may occur as a result of loss of the pineal insulinostatic factor(s).

2,4-Dinitrophenol↗
PubMedDate not supplied

Chronobiology in mental retardation research: progress and prospects.

The premise of this review is that chronobiology, the science of biologic time structure and rhythms, is important in investigations concerning the etiology, mechanisms and effects of deficient mental adaptive development. Chronobiology is also shown to have potential importance in therapeutics and rehabilitation. Most of the information available now and supporting this wide-spread relevance of chronobiology relates to circadian rhythms, but physiological and behavioral rhythms having other cycle lengths also contribute. Recent findings in seven topic areas of chronobiology are reviewed with emphasis on facts and relationships actually or potentially important for consideration in mental retardation research. These are: 1) development of sleep and EEG patterns; 2) rhythmic susceptibility to seizures; 3) adrenocortical and dependent rhythms; 4) circadian rhythms in amino acids and biogenic amines; 5) rhythmic behaviors; 6) circadian rhythms in susceptibility and responses to drugs; and 7) circadian rhythms in human perception and performance.

Adrenal Cortex↗
PubMedDate not supplied

Circadian changes in adrenal dopamine-beta-hydroxylase activity: dependency of change at darkness onset, and the effect of pinealectomy, on animal strain and age.

In a previous study we found a daily darkness- and pineal-dependent rise in adrenal dopamine-beta-hydroxylase (DBH) activity in 4-month-old S1 rats. The present investigation shows that aged (12 to 14-month-old) S1 rats do not have such a change in DBH activity. Similarly in the relatively younger (100-day-old) rats of a different (Holtzman) strain such a change was not found. Also pinealectomy did not seem to have any effect on adrenal DBH in either of these two strains of rats, young or old at times just before and after the onset of darkness. In both S1 and Holtzman rats, the concentration of copper-sensitive endogenous inhibitors of DBH remained unaltered following the surgical extirpation of pineal. Photoperiodic change from light to dark also had no significant effect on the inhibitor content in these two strains of rats. It is concluded that there are age and strain dependencies in the behavior of adrenal DBH activity at the daily onset of darkness.

Adrenal Glands↗
PubMedDate not supplied

Modification of plasma dopamine-beta-hydroxylase activity by adrenal and pineal extirpations, and time of day dependency of changes.

Plasma level of dopamine-beta-hydroxylase (DBH; EC 1.14.2.1) activity has been considered important both as a diagnostic aid and as an indicator of temporal changes in sympathetic activity. The present study sought to evaluate the possible dependency of some phases of the circadian rhythm in plasma DBH on adrenal and pineal glands. Male Holtzman (albino) rats were shamoperated, adrenalectomized (AX), pinealectomized (PX) or both adrenalectomized and pinealectomized (AXPX) at 32-35 days of age and after acclimation to controlled conditions with a fixed, 12-h, daily photoperiod (LD 12:12). Animals were killed at selected times 15 days postoperatively, and plasma DBH was measured using a sensitive radioenzymatic method. Results from two successive experiments showed that there was significant reduction in plasma DBH in the AXPX animals, but that this was evident only during the middle of the dark phase. PX and AX alone did not bring about any change in the DBH activity at any of the two times tested. These results show that combined endocrine manipulations can alter the circulatory DBH activity level and that such changes can be evaluated only within the definition of a circadian pattern.

Adrenalectomy↗