Dietary xylitol in the prevention of experimental osteoporosis. Beneficial effects on bone resorption, structure and biomechanics
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Chapter 4. Materials and methods

Table of Contents
4.1. Animals
4.2. Experimental design
4.3. Analyses
4.4. Statistical analyses

4.1. Animals

Outbred Wistar (Bkl) rats were used in studies I, IV and V, and outbred Sprague-Dawley (Mol) rats in studies II and III, according to availability from the supplier. Male rats were used in studies I, II and IV, and female rats in studies III and V, which included the use of ovariectomy. The rats were provided by the Laboratory Animal Center, University of Oulu, Finland. The main background information about the animals, and about the experimental design in different studies is presented in Table 4-1.

Table 4-1. Main background data of the animals and of the experimental design.

	Study I	Study II	Study III	Study IV	Study V
Rats
strain	Wistar	S-D^*	S-D	Wistar	Wistar
sex	male	male	female	male	female
baseline age	9 wk	9 wk	10wk	12wk	12wk
final age	13 wk	13 wk	22wk	24wk	24wk
basal diet	R3^**	RM1^***	RM1	R3	RM1
Design
xylitol supplementation	5, 10, 20%	1M^****	10%	5, 10, 20%	10%
ovariectomy			x		x
[³H];-tetracycline labeling	x	x	x
trabecular bone volume			x	x	x
bone biomechanical tests				x	x
^S-D is Sprague-Dawley rat^R3 by Lactamin (Labfor, Stockholm, Sweden)^RM1 by Special Diet Services (Witham, Essex, UK)^**also 1M sorbitol, 1M D-mannitol and 1M erythritol were included in the study design

The animals were housed in cages (Makrolon III; Tecniplast, Buguggiate, Italy), two or three to a cage, on a bed of European aspen shavings in a temperature- and light-controlled room (21-23°C, 12-hour light-dark cycle). They were weighed weekly, and their food intake was measured. At the end of the experimental period the rats were killed using carbon dioxide, followed by decapitation.

The study protocols were approved by the Ethical Committee on Animal Experiments of the University of Oulu.