Intact Rodent Research Articles

Hormonal response of intact rodent uterus in organ culture

Organ culture of hamster uterus was undertaken to test uterine tissue response to hormonal stimulus. Graded doses of progesterone and estradiol supplements to standard liquid medium permitted choice of optimal hormonal conditions for maintaining the endometrium. The selection of the most ideally supplemented medium was based on measurements of endometrial cell heights and histological appearance of the tissue sections; this medium, containing 4.0 μg/ml each of progesterone and estradiol, permitted maintenance of 8.0 mm lengths of hamster uterine tube (longitudinally opened) for seven days without necrosis.

Experimental and Clinical Experience With Gastric Freezing

Successful gastric freezing designed to achieve protracted periods of achlorhydria depends upon the attainment of uniform mucosal-temperature depression over the period of perfusion, an objective regularly achieved on freezing the isolated canine gastric pouch and the intact rodent stomach. This aim is facilitated by the use of four balloon-mucosal interface thermocouples, high collant flow rates, uniform coolant dispersion, perfusion with a nontoxic coolant, and rewarming of the stomach on conclusion of the procedure. Maintenance of balloon-mucosal interface temperatures in the range of -10 C to -11 C for six to seven minutes is optimal but not often registered on all thermocouples. Up to Jan 1, 1966, a total of 698 patients with manifestations of peptic ulcer and 10 patients with esophageal varices had undergone 1,021 episodes of freezing without hospital mortality. Postfreeze bleeding or gastric ulcer or both occurred in 7.5%. Since institution of rapid postfreeze gastric rewarming no complications have been observed. Almost uniform initial relief of pain and a high incidence of ulcer-crater healing were observed. Of those patients undergoing gastric freezing more than 24 months ago, 40% were either asymptomatic or experienced only minimal symptoms.

The Spleen-Thymus Weight Response to Total-Body X-Irradiation in the Adrenalectomized Rat and Mouse

The lymphatic system, including the spleen and thymus, undergoes a striking dissolution when the intact rodent is stressed (1, 2), exposed to total-body irradiation (3), or given adequate doses of either active adrenal corticoids or ACTH (4, 5). The adrenalectomized animal, although still responsive to corticoids, no longer shows the lymphoid response to stress (1, 2). On this basis, it has been reasoned that the lymphoid response to stress is mediated through the adrenal cortex. By considering ionizing radiation as a nonspecific stress, it is tempting to include it in this hypothesis, and, in fact, there is reason to believe that the in vivo lymphocyte response to X-irradiation can be an abscopal or indirect effect (6-8). This study was designed to test this point by determining the X-ray response of splenic and thymic weight in control, sham-operated, and adrenalectomized animals. The mouse was initially chosen for study; however, the high incidence of accessory and recurrent adrenal function with this preparation made it advisable to confirm the results in the rat. The experimental technique of Carter et al. was followed (3); however, their method of presenting and analyzing the response was substantially changed.