Erratum

Vesicular fragments of biomembranes either induced or present as vesicles inside cells, have diameters which fall into two geometric series. Cells with intact cytoskeletons can take up a range of sizes but at mitosis, the cytoskeleton disappears, the cells round up and the plasma membrane can be considered as a vesicle in a stable phase which according to the theory should fall within one of the two possible geometric series. Thus, the size of the mother cell at mitosis and hence of the daughter cells are determined by these geometric series. The diameters of lymphoid cells fall into series which are consistent with the theory.     

Behavioral and cardiac responses after intracerebroventricular corticotropin-releasing hormone (CRH) administration: role of adrenal cortical hormones.

Intracerebroventricularly (icv) administered corticotropin-releasing hormone (CRH) produces a dose-dependent increase in heart rate in association with behavioral activation. The present study was designed to investigate whether these CRH-induced responses are dependent on adrenal function. The effects of adrenalectomy (ADX) and subsequent corticosterone replacement were studied. Administration icv of 300 ng of CRH failed to produce behavioral activation and tachycardia in ADX rats. Corticosterone replacement restored the CRH-induced behavioral response to preoperative levels, whereas the CRH-induced tachycardia was partially restored. This latter result may be related to the fact that the baseline heart rate of ADX animals appeared to be significantly higher than that of corticosterone-treated ADX animals. It is concluded that circulating adrenal corticosterone in ADX rats is involved in the expression of the behavioral and cardiac effect of central CRH.