The effect of a bisphosphonate on bone volume and eggshell structure in the hen

Abstract

SUMMARYBisphosphonates, used in the prevention and treatment of osteoporosis, in man, can prevent bone loss in experimental models of osteoporosis in mammals. In egg-laying hens there is a high incidence of bone fractures which are due to osteoporosis. Alendronate, a bisphosphonate, was given to three groups of hens in mid-lay. Different doses of alendronate were given to each group and group 4 was a control. The birds were killed after 2 weeks of treatment. The hens receiving the highest dosage of alendronate (1 mg/kg every 2nd day) ceased laying and had reduced serum calcium concentrations. Lower dosages of alendronate (0.1 and 0.01 mg/kg every 2nd day) resulted in normal egg production and serum calcium concentrations. Egg shells with ultra-structural features indicative of reduced shell quality were produced by hens on the two higher dosages, but the egg shells from the controls and from the hens on the lowest dosage were considered normal. When alendronate was administered to hens in mid-lay there was no effect on trabecular bone volumes, but there was a reduction in mean medullary bone volume in some groups.In a second experiment, pullets were treated with alendronate (0.01 mg/kg twice a week) before the onset of lay. The pullets were killed after laying their first egg. In the pullets treated with alendronate, this protocol resulted in a significantly greater volume of trabecular (structural) bone at the onset of lay.

Effect of alendronate on post-traumatic osteoarthritis induced by anterior cruciate ligament rupture in mice

“…ALN-L mice (n = 30) received doses of 40 μg/kg/dose, while ALN-H mice (n = 30) received doses of 1,000 μg/kg/dose. The low-dose and high-dose treatments were chosen to represent the high and low range of effective doses from previous studies [10,19]. VEH mice (n = 30) were injected twice weekly with a vehicle solution (PBS).…”

An egg ist ein ei, es un huevo, est un oeuf

“…Continued research in this field at the Roslin Institute will serve to highlight whether husbandry, nutritional and genetic factors share an equal load in the predisposition to this crippling condition. Work by Thorp et al (1993) demonstrated the effects of the addition of a bisphosphonate on bone volume and eggshell structure in the hen. The authors concluded that treatment with alendronate has a potential role in preventing trabecular bone loss during lay and that the shell response to the inclusion of the drug was dose dependent.…”

Skeletal disorders in the fowl: A review

“…Aminohydroxybutane bisphosphonate (Alendronate, Merck, Sharp and Dohme Research Laboratories) inhibits trabecular bone loss in immobilized (Thompson et al, 1990) and ovariectomised (Seedor et ah, 1991) rats. A recent study has established that Alendronate is pharmacologically activity in egg-laying hens and has the potential to reduce the incidence and severity of osteoporosis (Thorp et al, 1993d). In man, osteoporosis can be prevented by the maximisation and maintenance of peak bone volume (Bhalla, 1993).…”

“…The lesion is morphologically characterised by an accumulation of chondrocytes that appear to be unable to differentiate past a prehypertrophic (transitional) stage. The altered expression of matrix proteins and cellular enzymes by these cells suggests that there is a malfunction of the variety of autocrine and paracrine factors that control chondrocyte differentiation (Farquharson et al, 1992;Thorp et al, 1993d). TGFrjß is produced by growth plate chondrocytes (Rosier et al, 1989) and may regulate chondrocyte differentiation (Seyedin et al, 1985;Gelb et al, 1990;ten Dijke et al, 1990).…”