Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes?
The objective of the present study was to examine whether hypothyroidism affects the reproductive system of adult female rats by evaluating ovarian morphology, uterus weight and the changes in serum and pituitary concentrations of prolactin and gonadotropins. Three-month-old female rats were divided...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
2001-01-01
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| Series: | Brazilian Journal of Medical and Biological Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000900015 |
| _version_ | 1818196642684207104 |
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| author | Armada-Dias L. Carvalho J.J. Breitenbach M.M.D. Franci C.R. Moura E.G. |
| author_facet | Armada-Dias L. Carvalho J.J. Breitenbach M.M.D. Franci C.R. Moura E.G. |
| author_sort | Armada-Dias L. |
| collection | DOAJ |
| description | The objective of the present study was to examine whether hypothyroidism affects the reproductive system of adult female rats by evaluating ovarian morphology, uterus weight and the changes in serum and pituitary concentrations of prolactin and gonadotropins. Three-month-old female rats were divided into three groups: control (N = 10), hypothyroid (N = 10), treated with 0.05% 6-propyl-2-thiouracil (PTU) in drinking water for 60 days, and T4-treated group (N = 10), receiving daily sc injections of L-thyroxine (0.8 µg/100 g body weight) during the last 10 days of the experiment. At the end of 50 days of hypothyroidism no hypothyroid animal showed a regular cycle, while 71% of controls as well as the T4-treated rats showed regular cycles. Corpora lutea, growing follicles and mature Graafian follicles were found in all ovaries studied. The corpora lutea were smaller in both the hypothyroid and T4-replaced rats. Graafian follicles were found in 72% of controls and only in 34% of hypothyroid and 43% of T4-treated animals. Serum LH, FSH, progesterone and estradiol concentrations did not differ among the three groups. Serum prolactin concentration and the pituitary content of the three hormones studied were higher in the hypothyroid animals compared to control. T4 treatment restored serum prolactin concentration to the level found in controls, but only partially normalized the pituitary content of gonadotropins and prolactin. In conclusion, the morphological changes caused by hypothyroidism can be a consequence of higher prolactin production that can block the secretion and action of gonadotropins, being the main cause of the changes observed. |
| first_indexed | 2024-12-12T01:37:20Z |
| format | Article |
| id | doaj.art-14593376a2af44959fbcb455a13cc144 |
| institution | Directory Open Access Journal |
| issn | 0100-879X 0034-7310 |
| language | English |
| last_indexed | 2024-12-12T01:37:20Z |
| publishDate | 2001-01-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-14593376a2af44959fbcb455a13cc1442022-12-22T00:42:48ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X0034-73102001-01-0134912091215Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes?Armada-Dias L.Carvalho J.J.Breitenbach M.M.D.Franci C.R.Moura E.G.The objective of the present study was to examine whether hypothyroidism affects the reproductive system of adult female rats by evaluating ovarian morphology, uterus weight and the changes in serum and pituitary concentrations of prolactin and gonadotropins. Three-month-old female rats were divided into three groups: control (N = 10), hypothyroid (N = 10), treated with 0.05% 6-propyl-2-thiouracil (PTU) in drinking water for 60 days, and T4-treated group (N = 10), receiving daily sc injections of L-thyroxine (0.8 µg/100 g body weight) during the last 10 days of the experiment. At the end of 50 days of hypothyroidism no hypothyroid animal showed a regular cycle, while 71% of controls as well as the T4-treated rats showed regular cycles. Corpora lutea, growing follicles and mature Graafian follicles were found in all ovaries studied. The corpora lutea were smaller in both the hypothyroid and T4-replaced rats. Graafian follicles were found in 72% of controls and only in 34% of hypothyroid and 43% of T4-treated animals. Serum LH, FSH, progesterone and estradiol concentrations did not differ among the three groups. Serum prolactin concentration and the pituitary content of the three hormones studied were higher in the hypothyroid animals compared to control. T4 treatment restored serum prolactin concentration to the level found in controls, but only partially normalized the pituitary content of gonadotropins and prolactin. In conclusion, the morphological changes caused by hypothyroidism can be a consequence of higher prolactin production that can block the secretion and action of gonadotropins, being the main cause of the changes observed.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000900015hypothyroidismprolactingonadotropinsfolliculogenesisestrous cycle |
| spellingShingle | Armada-Dias L. Carvalho J.J. Breitenbach M.M.D. Franci C.R. Moura E.G. Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? Brazilian Journal of Medical and Biological Research hypothyroidism prolactin gonadotropins folliculogenesis estrous cycle |
| title | Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? |
| title_full | Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? |
| title_fullStr | Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? |
| title_full_unstemmed | Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? |
| title_short | Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes? |
| title_sort | is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes |
| topic | hypothyroidism prolactin gonadotropins folliculogenesis estrous cycle |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000900015 |
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