Ultrasound Measurements of Testicular Size After Exposure to Cisplatin Chemotherapy in Adult Male Rats ^†

Abstract

Ultrasound has been used to diagnose many diseases in human and veterinary medicine, with excellent results. The present study aimed to assess the effect of cisplatin on testicular size using ultrasound imaging. The study was conducted on adult male rats divided into two equal groups: a control group (C) and an experimental group (CP) which received an intraperitoneal injection (I.P.) of 5 mg/kg cisplatin once a week for two consecutive weeks on day 6 (d6) and d12 of the experiment. After a period of 3 days following each injection, an ultrasound scan was performed to measure testicular volume following exposure to cisplatin (CP). The results indicate that testicular size increased significantly after the first dose (d6) (L: 1.67 ± 0.09, W: 0.91 ± 0.10) compared with the control group (L: 1.53 ± 0.07, W: 0.92 ± 0.03) and continued to increase after the second dose (d12) (L: 1.96 ± 0.18, W: 0.98 ± 0.11). In conclusion, these results indicate that the use of ultrasound technology to monitor testicular size after each dose produced excellent and very clear results, enabling testicular lesions to be diagnosed after cisplatin chemotherapy without the need for surgery or dissection.

1. Introduction

Cisplatin (CP) is the first member of the platinum group of antitumor agents and is known to be particularly effective against various types of cancer [1]. Despite its effectiveness, it is highly toxic to the testicles when used regularly. Ultrasound has been shown to diagnose many organ diseases in small animal models [2]. One of the advantages of this technique is that it can identify organ and tissue lesions in living animals by measuring their decrease or increase in size in the absence of any other pathological symptoms in the organs. The aim of this study is to measure testicular size after exposure of animals (rats) to a moderate dose of cisplatin (5 mg/kg) in two stages, and to determine at what stage the testicles begin to decrease or increase, bearing in mind that the testicles may be enlarged under inflammatory conditions.

2. Materials and Methods

2.1. Chemicals

Cisplatin (CP) (diamminedichlorideplatinum (II), with the chemical formula cis-(Pt Cl₂ (NH₃)₂), manufactured by Mylan S.A.S, France, was used in our experiment at a concentration of 25 mg/25 mL.

2.2. Animals and Experimental Design

The study was carried out on 14 adult male rats, aged 10 weeks and weighing 190–210 g. They were maintained in plastic cages at a temperature of 24 ± 2 °C, a relative humidity of 55.5% and a 12 h light/dark cycle, with unlimited access to water and a standard diet. The study was conducted in two groups (07 rats/group): The first group received 5 mg/kg cisplatin (CP) (experimental group) by I.P. injection at day 6 (CP-d6) and day 12 (CP-d12) of experimentation, and the control group (C) received normal saline. After an interval of 3 days following each injection, an ultrasound image (Wisonic Piloter- Probe (15 MHz) manufactured in Shenzhen, China) was taken to measure testicular length and width after exposure to cisplatin.

2.3. Statistical Analysis

The results obtained (testicular length and width) were expressed as mean ± SEM. One-way ANOVA followed by Tukey’s post hoc test were performed using IBM SPSS Statistics 23.0 (IBM Corp., New York, NY, USA). The significance degree was set at p ≤ 0.05 (*).

3. Results and Discussion

The present study revealed that ultrasound measurements of testicular size show that (CP) causes a significant increase in testicular length, although no significant change in testicular width was observed (Figure 1 and Figure 2). This increase in testicular size after each administration of (CP) may be related to inflammation or testicular swelling. Nna et al. [3] have shown that cisplatin can induce inflammatory changes in testicular tissue. The fact that testicular width did not vary significantly may be related to the nature of the changes induced by (CP). It may also reflect the relative stability of blood vessels and micro vascularization, despite the increase in inflammation and the fact that cisplatin does not uniformly affect testicular tissue dimensions in all directions, which is in agreement with Şener et al. [4], who showed that cisplatin induces apoptosis and morphological alterations in the testes. Increased reactive oxygen species (ROS) production may also damage certain cells [5]. This damage may not affect the entire testis uniformly, resulting in asymmetry.

4. Conclusions

The findings of the present study confirm that the use of ultrasound provides higher-resolution images for monitoring the size and progression of testicular lesions in rats after exposure to cisplatin chemotherapy without the need for surgery or autopsy.