PURPOSE: to evaluate the morphological changes in murine lacrimal glands by metoclopramide-induced hyperprolactinemia during the proestrus phase or pregnancy. METHODS: forty adult mice were divided into two groups: CTR1 (control) and MET1 (treated with metoclopramide). After fifty days, half of the mice were sacrificed. The remaining animals were mated, and then labeled as pregnant controls (CTR2). Part of these animals were treated with metoclopramide and constituted the metoclopramide-treated pregnant (MET2) group. The CTR2 and MET2 groups were sacrificed on the 6th day of pregnancy. The blood was collected for determination of the hormonal levels of estradiol and progesterone by a chemoluminescent method. The lacrimal glands were then removed, fixed in 10% formaldehyde and stained with HE. The morphometric analysis was performed using the Axion Vision program (Carl Zeiss) to measure acinar nuclear and cellular volumes. RESULTS: the nuclear and cellular volumes of the lacrimal glands in the MET1-(152.2±8.7; 6.3±1.6 µm³) and MET2-(278.3±7.9; 27.5±0.9 µm³) treated groups were lower than those in CTR1 (204.2±7.4; 21.9±1.3 µm³) and CTR2 (329.4±2.2; 35.5±2.0 µm³), respectively. There was a significant hormonal level reduction in the animals that received metoclopramide compared to controls (CTR1: estradiol = 156.6±42.2 pg/ml; progesterone = 39.4±5.1 ng/ml; MET1: estradiol = 108.0±33.1 pg/ml; progesterone = 28.0±6.4 ng/ml; CTR2: estradiol = 354.0±56.0 pg/ml; progesterone = 251.0±56.0 ng/ml; MET2: estradiol = 293.0±43.0 pg/ml, progesterone = 184.0±33.0 ng/ml). CONCLUSION: metoclopramide-induced hyperprolactinemia produced morphological signs of reduction of cellular activity in lacrimal glands during the proestrus phase and pregnancy. It is hypothesized that this effect might be related to the hyperprolactinemia-induced decrease in the hormonal production of estrogen and progesterone.
Hyperprolactinemia; Metoclopramide; Lacrimal gland; Mice
