| Author/Editor | Štiblar-Martinčič, D | |
| Title | Vpliv svetlobe in teme na mikroskopsko zgradbo ščitnice | |
| Translated title | The light-dark influence on microscopical structure of thyroid gland | |
| Type | monografija | |
| Place | Ljubljana | |
| Publisher | Medicinska fakulteta | |
| Publication year | 1991 | |
| Volume | str. 140 | |
| Language | slo | |
| Abstract | The influence of light-dark rhythm on morphology and function of follicular and parafollicular cells of thyroid gland has been examined on nine adult male BALB/c strain rats. Animals were divided into 3 groups and were exposed to different lighting conditions for 4 weeks as follows: group A 0h of light, group B 12h of light and group C 24h of light daily. Stereological analysis has been applied. Furthermore the influence of pinealectomy of morphology and function of follicular and parafollicular cells of thyroid gland has been examined on nine adult male Wistar strain rats. Animals were divided into 3 groups; group E were pinealectomized, group LE were shame pinealectomized and group K were left intact as controls. After identical experiments were performed, first in winter, second in summer period. Both stereological and biochemical analysis has been applied. In alternating ligh-dark rhythm it has been found that the thyroid glands from the group B have the least folded follicles containing the highest amount of colloid, the lowest values of follicular nuclear volume density, for nuclear-cytoplasmic ration of these cells and the lowest average nuclear volume, which is in accordance with the hypothesis stating the lowest activity of follicular cells is at natural rhythm of 12h light and 12h darkness. In the group C the highest values of thyroid activation index, of nuclear-cytoplasmic ratio of follicular cells, the hypertrophia of these cells were noted which support the hypothesis regarding the highest activity of follicular cells at permanent light. Significant higher num ber and average volume of parafollicular cells in the group A in comparison with the group B indicates the hypertrophia and hyperplasia of these cells during the permanent darkness.(trunc.) | |
| Descriptors | THYROID GLAND LIGHT DARKNESS CIRCADIAN RHYTHM HISTOLOGICAL TECHNIQUES MICE ANIMALS, LABORATORY PINEAL BODY SEASONS CALCITONIN CALCIUM TRIIODOTHYRONINE THYROXINE THYROTROPIN |