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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Female, Flow Cytometry, Histamine, Histidine Decarboxylase, Interferon-gamma, Male, Mice, Mice, Knockout, Pregnancy, Pregnancy, Animal, Sexual Behavior, Animal, Spleen.
user
Is impaired reproduction of histamine deficient ( histidine-decarboxylase knockout ) mice caused predominantly by a decreased male mating behavior? Context: Histamine induces a Th2 shift. As successful allopregnancy is characterized by a peripheral Th2 dominance, we investigated the role of histamine in reproduction. HDC knockout (HDC-/-) or wild-type (HDC+/+) mice kept on histamine-deficient or normal diet were mated. Appearance of vaginal plugs indicated day 0.5 of pregnancy. On day 10.5 uteri were inspected. Splenic IFN-gamma production and cytotoxic activity were determined. In HDC+/+ or HDC-/- females on normal diet, plugs appeared between 3 and 6 days. In 80% of the (HDC-/-)/(HDC-/-) matings on histamine-deficient diet, no vaginal plugs were observed for more than 1 month. After replacing males with the wild type, plugs appeared within 3 days. In HDC-/- mice, litter size was lower than in HDC+/+ animals. Cytotoxicity and IFN-gamma production were significantly increased in non-pregnant histamine-deficient mice, but not in pregnant mice.
assistant
Histamine affects male mating behavior, but is not indispensable for successful pregnancy. Final Decision: yes