Search Results

You are looking at 1 - 1 of 1 items for

  • Author: I Varga x
  • Refine by access: Content accessible to me x
Clear All Modify Search
E Pap
Search for other papers by E Pap in
Google Scholar
PubMed
Close
,
K Racz
Search for other papers by K Racz in
Google Scholar
PubMed
Close
,
JK Kovacs
Search for other papers by JK Kovacs in
Google Scholar
PubMed
Close
,
I Varga
Search for other papers by I Varga in
Google Scholar
PubMed
Close
,
E Buzas
Search for other papers by E Buzas in
Google Scholar
PubMed
Close
,
B Madarasz
Search for other papers by B Madarasz in
Google Scholar
PubMed
Close
,
C Foldes
Search for other papers by C Foldes in
Google Scholar
PubMed
Close
,
C Szalai
Search for other papers by C Szalai in
Google Scholar
PubMed
Close
,
T Watanabe
Search for other papers by T Watanabe in
Google Scholar
PubMed
Close
,
H Ohtsu
Search for other papers by H Ohtsu in
Google Scholar
PubMed
Close
,
A Ichikawa
Search for other papers by A Ichikawa in
Google Scholar
PubMed
Close
,
A Nagy
Search for other papers by A Nagy in
Google Scholar
PubMed
Close
, and
A Falus
Search for other papers by A Falus in
Google Scholar
PubMed
Close

Histamine is synthesized in cells by histidine decarboxylase (HDC). HDC-deficient knockout (KO) mice lack functional HDC and histamine in the tissues. In the present study we used this in vivo model for studying the role of HDC deficiency in the regulation of male steroid hormone metabolism. In agreement with earlier studies showing the lack of effects of central histamine on the basal secretion of gonadotrope hormones, we found no difference with in situ hybridization in the expression of GnRH in the hypothalamus of wild type and KO mice. The tissue concentrations of testosterone and several androgenic steroids were significantly elevated in the testes but not in the adrenal glands of HDC-KO mice. In contrast, serum estradiol levels failed to show a significant difference between the two groups. The weight of the testes was significantly smaller in both 7-day-old and adult KO mice. The ultrastructure of the adult testis indicated elevated steroid synthesis with more tightly coiled membranous whorls in Leydig cells. The present results suggest that changes in reproductive functions and sex steroid secretion in male HDC-KO mice are not due to altered hypothalamic GnRH expression but are probably related to definite modifications during fetal development of KO mice reinforced later by the lack of the effect of peripheral histamine. This may provide in vivo evidence that peripheral histamine is an important regulatory factor of male gonadal development during embryogenesis and of sex steroid metabolism later in adulthood.

Free access