Anorexia after adrenalectomy in gold thioglucose-treated obese mice.

The effects of adrenalectomy on food intake, weight gain, plasma glucose, and corticosterone levels were investigated in normal untreated controls and gold thioglucose-(GTG) treated hyperphagic obese mice. Adrenalectomy of normal untreated mice was followed by a transient reduction in food intake and body weight with a return, after approximately 7 days, to levels which paralleled those of untreated sham-operated mice. Plasma corticosterone levels were significantly depressed in all untreated adrenalectomized mice.

Inhibition by hypophysectomy of the hyperphagia and obesity following gold thioglucose.

The effect of hypophysectomy in mice previously treated with gold thioglucose (GTG) was studied with respect to changes in food intake and development of obesity. As expected, all mice treated with GTG alone exhibited lesions in the ventromedial hypothalamus (VMH), hyperphagia and obesity. Hypophysectomy of GTG treated mice prevented the appearance of hyperphagia and obesity.

Gold thioglucose-induced hypothalamic damage, hyperphagia, and obesity: dependence on the adrenal gland.

Previous studies from our laboratory suggested that adrenal hormones may participate, directly or indirectly, in the hypothalamic mechanism involved in the regulation of food intake. In the present studies, the effect of adrenalectomy on the development of gold thioglucose (GTG)-induced hyperphagia and obesity in mice was investigated. As expected, damage to the ventromedial hypothalamus by GTG was followed by hyperphagia and obesity.

Mediation by serotonin of gold thioglucose-induced necrosis of the ventromedial hypothalamus.

Agents that lower serotonin levels or inhibit serotonin action prevent GTG-indurea and that such damage leads to abnormally increased capillary permeability. Since the VMH is rich in serotonin and since serotonin is a potent oedema-producing agent mice, these findings indicate that the production of necrosis by GTG is mediated by release of serotonin from the damaged pericapillary processes.

Action of gold thioglucose on pericapillary structures in the ventromedial hypothalamus.

The administration of GTG to mice leads to death of all structures in a circumscribed area of the VMH as a result of loss of blood circulation. The loss of circulation is due to damage by GTG of neural processes adjacent to some of the capillaries in this area; damage to these processes leads to abnormal capillary permeability. Pericapillary damage occurs under conditions where capillary damage and consequent necrosis are prevented.