[Study of in vitro cultured microencapsulated adrenal cortical tissues of rats]

In order to investigate the growth of in vitro cultured microencapsulated adrenal cortical tissues of rats, we produced the microcapsules by using sodium alginate, calcium chloride and poly-L-lysine, etc. The adrenal glands were taken out of 24 rats, half of the adrenal glands were microencapsulated (capsule group) while the other half were left free (noncapsule group). After 36 hours' in vitro culture, the concentrations of aldosterone and cortisol in culture solution were measured by radioimmunoassay. The two groups continued to be cultured for 24 and 36 hours with ACTH stimulation. The concentrations of aldosterone and cortisol at 24 and 36 hours were detected respectively. Parts of adrenal cortical tissues were observed under light microscope and electron microscope. The results showed that the concentrations of aldosterone and cortisol in the microencapsulated adrenal cortical tissues were significantly higher than those of noncapsule group (P < 0.01). In the capsule group, the concentration of cortisol after 36 hours' ACTH stimulation was significantly higher than that before ACTH stimulation (P < 0.01). After 24 and 36 hours' ACTH stimulation, the concentrations of aldosterone and cortisol were significantly higher in the capsule group than in the noncapsule group. In the noncapsule group, regardless of ACTH stimulation, no significant change was seen in the concentration of aldosterone and cortisol (P > 0.05). The cellular structure of adrenal tissues remained intact under light microscopic and electron microscopic observations, and the cells remained alive well. These data suggest that in vitro cultured cells of microencapsulated adrenal cortical tissues remain alive well. Microcapsule has not influenced the secretory function of adrenal tissues. Microencapsulated tissues have a good response to ACTH stimulation.