The reproductive inhibitory effects of levonorgestrel, quinestrol, and EP-1 in Brandt’s vole (Lasiopodomys brandtii)

Abstract

Background Rodent pests can inflict devastating impacts on agriculture and the environment, leading to significant economic damage associated with their high species diversity, reproductive rates and adaptability. Fertility control methods could indirectly control rodent pest populations as well as limit ecological consequences and environmental concerns caused by lethal chemical poisons. Brandt’s voles, which are common rodent pests found in the grasslands of middle-eastern Inner Mongolia, eastern regions of Mongolia, and some regions of southern Russia, were assessed in the present study. Methods We evaluated the effects of a 2-mg/kg dose of levonorgestrel and quinestrol and a 1:1 mixture of the two (EP-1) on reproductive behavior as well as changes in the reproductive system, reproductive hormone levels, and toxicity in Brandt’s voles. Results Our results revealed that all three fertility control agents can cause reproductive inhibition at a dosage of 2 mg/kg. However, quinestrol caused a greater degree of toxicity, as determined by visible liver damage and reduced expression of the detoxifying molecule CYP1A2. Of the remaining two fertility control agents, EP-1 was superior to levonorgestrel in inhibiting the secretion of follicle-stimulating hormone and causing reproductive inhibition. We believe that these findings could help promote the use of these fertility control agents and, in turn, reduce the use of chemical poisons and limit their detrimental ecological and environmental impacts.

Impact of contraceptive hormones on the reproductive potential of male and female commensal black rats (Rattus rattus)

“…2017; Shi et al . 2020). Reproductive organs of males, sperm production, and sperm motility were all negatively affected by both hormones.…”

“…This is in contrast with studies in R. nitidius (Liu et al 2013) and Brandt's voles (Zhao et al 2007) which showed that quinestrol did not reduce the weight of the uterus or change its morphology. Edema in the uterus of treated animals has been suggested to be due to increases in estradiol and progesterone level and prolongation of estrogenic activity which results in swelling of the uterus (Su et al 2017;Shi et al 2020). Reproductive organs of males, sperm production, and sperm motility were all negatively affected by both hormones.…”

Impact of fertility versus mortality control on the demographics of Mastomys natalensis in maize fields

“… 2013 ; Zhang 2015 ; Shi et al . 2020 ). Fertility control does not immediately lower a population, but it prevents the build‐up of population eruptions (Stenseth et al .…”

Rodent management and cereal production in Asia: Balancing food security and conservation

“…Too little is known about conservation agriculture and the positive or negative effects of such practices on pest rodent population dynamics. New management approaches are on the horizon. One example is fertility control of rodent pests 104–106 . Another, although controversial, 107 is synthetic gene drive technology that may provide an opportunity to substantially influence the sex ratio of a rodent population 108 .…”