An experimental model is described to determine the relationship of oral contraceptives and hypertension by examining the effect of gonadal steroids on a strain of rats genetically predisposed to develop hypertension from a chronic excess of NaCl. 52 female salt-sensitive rats divided into 4 groups were maintained on a .38% salt diet during Weeks 3-5 of life while control blood pressure measurements were taken. Group A was then maintained on its diet and administered contraceptive steroids subcutaneously daily. Group B maintained its diet without change. The diet of Group C was changed to a 4% salt food and the animals were administered the steroids, while Group D received the 4% NaCl diet without the steroids. All treatments were continued for 38 weeks and blood pressure was maintained weekly. The rats receiving contraceptive steroids showed significantly lower body weight than those not receiving steroids (p=.0001). The animals on the high salt diet had significantly higher blood pressure than those rats on the low salt diet (p=.0001). Group C rats had significantly higher blood pressure than Group D (p=.0001), but Group A rats had significantly lower blood pressure than Group B (p=.006). The administration of contraceptive steroids enhanced the hypertension of the rats receiving the high salt diet but had no relationship to hypertension in the rats receiving the low salt diet. The steroids did not affect animal survival, but the salt intake did. The mechanism of the hypertension enhancement described here is unknown, but this experimental model should prove useful for further research.
In March 2006, Merck KGaA announced a € bid for Schering AG , which had been founded in 1851 and by 2006 had annual gross revenue of around €5 billion  and employed about 26,000 people in 140 subsidiaries worldwide.  Bayer responded with a white knight bid and in July acquired the majority of shares of Schering for €,  and in 2007, Bayer took over Schering AG and formed Bayer Schering Pharma. The acquisition of Schering was the largest take-over in Bayer's history,  : 49–52  and as of 2015 this was one of the ten biggest pharma mergers of all time.