Secretory Phase Of Cycle Research Articles

Influence of oral contraceptives on normal human breast epithelial proliferation

Researchers studied the influence of different formulations of oral contraceptives (OC) on breast tissue response and resting breast proliferation in response to menstrual cycles. They accepted only benign lesions mostly fibroadenomas of breast tissue from women less than 35 years old already undergoing biopsy. In order to have a good yield of parenchymal elements pathologists applied stereomicroscopic dissection techniques of vitally stained fresh tissue slices (from adjacent normal tissue). The tissues were then incubated with 3H-thymidine under hyperbaric oxygen situations for 1 hour and subsequently processed for autoradiography. Interviewers questioned patients the day of surgery to determine menstrual and obstetric history and details of OC use. Interviewers recorded the date of onset of the last menstrual period and gave the women a card to mark the date of the next menses. Researchers only accepted cycles of 26-30 days and averaged the data to a 28 day cycle for graphic plotting. TLI values for the 127 women with natural cycles ranged form .01-11.66 with a significant difference between the and phases. TLI values for the 144 women with artificial (OC) cycles spanned from .05-10.43 also with a significant difference between the phases. Researchers noted a significant difference in the level of response in the 8-13 day period of the proliferative phase of the artificial cycle and the natural cycle. Additionally maximal response in the late secretory phase of the artificial cycle was significantly higher than the equivalent phases of the natural cycle. Researchers also compared proliferation according to progestin content of the OC using 4 groups: low dose combined; high dose combine; sequential combined; and continuous progestin alone. ALL comparisons of the different types of OCs within either proliferative or secretory phases of the cycle proved to be not significantly different. When researchers studied the effect of parity however major differences appeared. Nulliparous women who used OCs had a higher response in the secretory phase than did nulliparous natural cycles. Conversely parous OC users did not respond in the secretory phase. When comparing between phases in nulliparous and parous women OC users researchers found a highly significant difference (p=.0036). The influence of parity on breast response in OC users is of major relevance yet researchers and health practitioners must exercise caution in its interpretation because of the possibility of confounding factors. It is not yet known whether the factors regulating these responses are a direct or indirect consequence with regard to parity and OC use. Evidence supports both and therefore further research is necessary.

The effect of cerebral ischemia on the ultrastructure of the hypothalamo-neurohypophysial system of the mongolian gerbil. The supraoptic and paraventricular nuclei.

The results of ultrastructural studies of the nucleus supraopticus (SON) and n. paraventricularis (PVN) of male mongolian gerbils subjected to experimental cerebral ischemia induced by 10 min bilateral occlusion of the common carotids are reported. Marked alterations concerned endocrine neurons, some neurosecretory axons and synaptic terminals as well as astroglia cells. Basing on the electron density of cytoplasmic ground, two varieties of endocrine neurons, that is 'light' and 'intermediate', were designated in both SON and PVN nuclei. These findings suggest that during cerebral ischemia the SON and PVN neurons become activated (Golgi complex and granular endoplasmic reticulum enlargement) and that they represent different phases of secretory cycle of a single cell type. However, in SON nucleus some neurons were probably damaged because they had the appearance of decidedly 'dark' cells. With respect to some neurosecretory axons, the finding of externally lying lamellar whorls indicates ischemic injury of the axons. Similar significance may be attributed to some synaptic terminals which showed an increased polymorphism of synaptic vesicles and vesicular aggregation. There was marked swelling of perivascular astroglia cells and change of their cytoplasm in both SON and PVN nuclei. Moreover, the swollen astroglia cells contacted those 'dark' neurons in SON nucleus. The present study indicates that SON and PVN nuclei are highly sensitive to application of cerebral ischemia. At the same time perivascular injury may suggest involvement of astroglia cells in the production of subsequent changes in the SON and PVN neuropil.

Hormonal control of the secretory immune system of the human uterine cervix

A quantitative immunohistological study of IgA-containing plasma cells in the human uterine cervix has shown that the number of such cells increases during the late secretory phase of the menstrual cycle but decreases in the early secretory phase of the cycle, in pregnancy, in cystic glandular hyperplasia of the endometrium and after the menopause. These results are interpreted as indicating that progesterone causes an increased plasma cell localisation in the cervix whilst oestrogens cause a decrease: it is suggested that this reflects hormonal control of a receptor mechanism and that this receptor can also be blocked by high levels of LH or hCG. The number of cervical epithelial cells containing secretory component (SC) is increased in the late secretory phase of the menstrual cycle, in users of contraceptive pills and in pregnancy. It is suggested that progesterone acts to increase the intra-epithelial content of SC and that no other hormonal factor need be involved.

Chronic effect of TRH and LRH upon a series of basophils along with the serum and pituitary TSH, LH and FSH concentration.

Chronic subcutaneous injections with synthetic TRH (10μg/0.2ml of gelatine-saline) for 21 days slightly raised not only serum TSH but also serum LH concentration; those for 7 days tended to diminish the serum LH and FSH concentration. The magnitude of rise in the serum TSH was approximately equivalent to 1/5 of the value 30 days after a single injection with the same dose of TRH. The injections of synthetic LRH (5μg/0.2ml) for 21 days, on the other hand, raised the serum LH concentration 3.5 times as high as a single injection did. Pituitary TSH concentration was lowered conspicuously after TRH injections for 21 days; pituitary LH concentration was diminished remarkably after LRH injections for 21 days. Serum FSH concentration was not changed by the same LRH injection, while pituitary FSH concentration was diminished. Injections of TRH and LRH in combination for 7 or 21 days lowered the pituitary LH and FSH content more extensively than the separate LRH injection for 7 or 21 days. Some of our assay data may suggest the possible: synergistic or countervailing influences of the releasing hormones upon the secretion of the other trophic hormones. This is contradictory to the concept “one releasing hormone is responsible for one target cell”. This discrepancy may be explained by our working hypothesis as to the secretory cycle of the basophil.It was tentatively concluded from our morphological manifestation that each releasing hormone did not act limitedly upon one target cell but universally upon a series of basophils. Both TRH and LRH exerted the analogous morphokinetic functions to convert the II-type cell (classical thyrotroph) into the III-type cells (classical LH-gonadotrophs) which are destined to turn into the III/IV-and IV-type cells (classical FSH-gonadotrophs), and to revert them to the original TI-type cells in the course of secretory cycle. There was a morphological evidence to show that the releasing. hormone might accelerate the rotation of secretory cycle of the basophil. Our working. hypothesis is that the various types of basophils may not be independent of each other, but modify their shape and property according to the different phases of secretory cycle, i. e., synthesizing, storing, secreting and resting phases. The II/III-and III-type cells were particularly accumulated after a long-term TRH injection; the IV/II-or II-type cells were accumulated but the IV-type cells were diminished in number after a separate LRH injection or the TRH and LRH injections in combination. The accumulation of the resting cells (IV/II-type) may account for the temporal stabilization of secretory cycle by the chronic injection.